The Washington University Clinical Research Center has now been in operation for 12 years and consists of a 25 bed adult unit and 8 bed pediatric facility operated as independent nursing services but functioning under a single administration and sharing dietary and core laboratory resources. Both the adult and pediatric units are designed so that the acutely ill as well as the ambulatory patient and normal volunteer can be studied. The Center provides for the hospitalization of patients in a setting in which expert dietary control, skillful intensive nursing care and facilities for specialized studies can be performed. The Clinical Research Center Core Laboratories provide assistance for specialized determinations used by multiple investigations and represents a research resource for the development of new analytical procedures. All faculty members of the clinical and basic science departments of the Washington University School of Medicine who wish to pursue clinical investigation and have research protocols approved by the University Committee on Human Experimentation and by the Advisory Committee of the Clinical Research Center may use the resources of the Center. Although the major function of the Clinical Research Center is clinical investigation, it also provides opportunities for undergraduate and post-graduate training in clinical investigation.